Fission and fusion explosives intermediate between chemical and conventional nuclear devices in yield.

Dating back to the late Information and Interplanetary Ages, these weapons had yields in the range of 1 to 100 ton equivalents of chemical explosives, which was the gap which had formally separated conventional weapons from nuclear weapons.

These relatively low-yield nuclear explosives do not (strictly speaking) qualify as weapons of mass destruction. Physical processes which were and are used to make such low-yield nuclear weapons, or to make compact non-fission triggers for large scale thermonuclear explosions, include sub-critical fission-burn, magnetic compression, super-heavy elements, antimatter, nuclear isomers, metallic hydrogen and lasers with intensities higher than 1E19 W/cm2.

Weapons of this type are still widely used, especially in the Outer Volumes and feral regions, where their ease of manufacture makes them appealing. They are also more widely used for mining demolitions in low tech and ludd systems with limited access to nanotech.